How do I replace \n with empty space?
I get an empty literal error if I do this:
string temp = mystring.Replace('\n', '');
String.Replace('\n', '') doesn't work because '' is not a valid character literal.
If you use the String.Replace(string, string) override, it should work.
string temp = mystring.Replace("\n", "");
As replacing "\n" with "" doesn't give you the result that you want, that means that what you should replace is actually not "\n", but some other character combination.
One possibility is that what you should replace is the "\r\n" character combination, which is the newline code in a Windows system. If you replace only the "\n" (line feed) character it will leave the "\r" (carriage return) character, which still may be interpreted as a line break, depending on how you display the string.
If the source of the string is system specific you should use that specific string, otherwise you should use Environment.NewLine to get the newline character combination for the current system.
string temp = mystring.Replace("\r\n", string.Empty);
or:
string temp = mystring.Replace(Environment.NewLine, string.Empty);
This should work.
string temp = mystring.Replace("\n", "");
Are you sure there are actual \n new lines in your original string?
string temp = mystring.Replace("\n", string.Empty).Replace("\r", string.Empty);
Obviously, this removes both '\n' and '\r' and is as simple as I know how to do it.
If you use
string temp = mystring.Replace("\r\n", "").Replace("\n", "");
then you won't have to worry about where your string is coming from.
One caveat: in .NET the linefeed is "\r\n". So if you're loading your text from a file, you might have to use that instead of just "\n"
edit> as samuel pointed out in the comments, "\r\n" is not .NET specific, but is windows specific.
What about creating an Extension Method like this....
public static string ReplaceTHAT(this string s)
{
return s.Replace("\n\r", "");
}
And then when you want to replace that wherever you want you can do this.
s.ReplaceTHAT();
Best Regards!
Here is your exact answer...
const char LineFeed = '\n'; // #10
string temp = new System.Text.RegularExpressions.Regex(
LineFeed
).Replace(mystring, string.Empty);
But this one is much better... Specially if you are trying to split the lines (you may also use it with Split)
const char CarriageReturn = '\r'; // #13
const char LineFeed = '\n'; // #10
string temp = new System.Text.RegularExpressions.Regex(
string.Format("{0}?{1}", CarriageReturn, LineFeed)
).Replace(mystring, string.Empty);
string temp = mystring.Replace("\n", " ");
#gnomixa - What do you mean in your comment about not achieving anything? The following works for me in VS2005.
If your goal is to remove the newline characters, thereby shortening the string, look at this:
string originalStringWithNewline = "12\n345"; // length is 6
System.Diagnostics.Debug.Assert(originalStringWithNewline.Length == 6);
string newStringWithoutNewline = originalStringWithNewline.Replace("\n", ""); // new length is 5
System.Diagnostics.Debug.Assert(newStringWithoutNewline.Length == 5);
If your goal is to replace the newline characters with a space character, leaving the string length the same, look at this example:
string originalStringWithNewline = "12\n345"; // length is 6
System.Diagnostics.Debug.Assert(originalStringWithNewline.Length == 6);
string newStringWithoutNewline = originalStringWithNewline.Replace("\n", " "); // new length is still 6
System.Diagnostics.Debug.Assert(newStringWithoutNewline.Length == 6);
And you have to replace single-character strings instead of characters because '' is not a valid character to be passed to Replace(string,char)
I know this is an old post but I'd like to add my method.
public static string Replace(string text, string[] toReplace, string replaceWith)
{
foreach (string str in toReplace)
text = text.Replace(str, replaceWith);
return text;
}
Example usage:
string newText = Replace("This is an \r\n \n an example.", new string[] { "\r\n", "\n" }, "");
Found on Bytes.com:
string temp = mystring.Replace('\n', '\0');// '\0' represents an empty char
Related
I have the following input:
string txt = " i am a string "
I want to remove space from start of starting and end from a string.
The result should be: "i am a string"
How can I do this in c#?
String.Trim
Removes all leading and trailing white-space characters from the current String object.
Usage:
txt = txt.Trim();
If this isn't working then it highly likely that the "spaces" aren't spaces but some other non printing or white space character, possibly tabs. In this case you need to use the String.Trim method which takes an array of characters:
char[] charsToTrim = { ' ', '\t' };
string result = txt.Trim(charsToTrim);
Source
You can add to this list as and when you come across more space like characters that are in your input data. Storing this list of characters in your database or configuration file would also mean that you don't have to rebuild your application each time you come across a new character to check for.
NOTE
As of .NET 4 .Trim() removes any character that Char.IsWhiteSpace returns true for so it should work for most cases you come across. Given this, it's probably not a good idea to replace this call with the one that takes a list of characters you have to maintain.
It would be better to call the default .Trim() and then call the method with your list of characters.
You can use:
String.TrimStart - Removes all leading occurrences of a set of characters specified in an array from the current String object.
String.TrimEnd - Removes all trailing occurrences of a set of characters specified in an array from the current String object.
String.Trim - combination of the two functions above
Usage:
string txt = " i am a string ";
char[] charsToTrim = { ' ' };
txt = txt.Trim(charsToTrim)); // txt = "i am a string"
EDIT:
txt = txt.Replace(" ", ""); // txt = "iamastring"
I really don't understand some of the hoops the other answers are jumping through.
var myString = " this is my String ";
var newstring = myString.Trim(); // results in "this is my String"
var noSpaceString = myString.Replace(" ", ""); // results in "thisismyString";
It's not rocket science.
txt = txt.Trim();
Or you can split your string to string array, splitting by space and then add every item of string array to empty string.
May be this is not the best and fastest method, but you can try, if other answer aren't what you whant.
text.Trim() is to be used
string txt = " i am a string ";
txt = txt.Trim();
Use the Trim method.
static void Main()
{
// A.
// Example strings with multiple whitespaces.
string s1 = "He saw a cute\tdog.";
string s2 = "There\n\twas another sentence.";
// B.
// Create the Regex.
Regex r = new Regex(#"\s+");
// C.
// Strip multiple spaces.
string s3 = r.Replace(s1, #" ");
Console.WriteLine(s3);
// D.
// Strip multiple spaces.
string s4 = r.Replace(s2, #" ");
Console.WriteLine(s4);
Console.ReadLine();
}
OUTPUT:
He saw a cute dog.
There was another sentence.
He saw a cute dog.
You Can Use
string txt = " i am a string ";
txt = txt.TrimStart().TrimEnd();
Output is "i am a string"
How can I replace Line Breaks within a string in C#?
Use replace with Environment.NewLine
myString = myString.Replace(System.Environment.NewLine, "replacement text"); //add a line terminating ;
As mentioned in other posts, if the string comes from another environment (OS) then you'd need to replace that particular environments implementation of new line control characters.
The solutions posted so far either only replace Environment.NewLine or they fail if the replacement string contains line breaks because they call string.Replace multiple times.
Here's a solution that uses a regular expression to make all three replacements in just one pass over the string. This means that the replacement string can safely contain line breaks.
string result = Regex.Replace(input, #"\r\n?|\n", replacementString);
To extend The.Anyi.9's answer, you should also be aware of the different types of line break in general use. Dependent on where your file originated, you may want to look at making sure you catch all the alternatives...
string replaceWith = "";
string removedBreaks = Line.Replace("\r\n", replaceWith).Replace("\n", replaceWith).Replace("\r", replaceWith);
should get you going...
I would use Environment.Newline when I wanted to insert a newline for a string, but not to remove all newlines from a string.
Depending on your platform you can have different types of newlines, but even inside the same platform often different types of newlines are used. In particular when dealing with file formats and protocols.
string ReplaceNewlines(string blockOfText, string replaceWith)
{
return blockOfText.Replace("\r\n", replaceWith).Replace("\n", replaceWith).Replace("\r", replaceWith);
}
If your code is supposed to run in different environments, I would consider using the Environment.NewLine constant, since it is specifically the newline used in the specific environment.
line = line.Replace(Environment.NewLine, "newLineReplacement");
However, if you get the text from a file originating on another system, this might not be the correct answer, and you should replace with whatever newline constant is used on the other system. It will typically be \n or \r\n.
if you want to "clean" the new lines, flamebaud comment using regex #"[\r\n]+" is the best choice.
using System;
using System.Text.RegularExpressions;
class MainClass {
public static void Main (string[] args) {
string str = "AAA\r\nBBB\r\n\r\n\r\nCCC\r\r\rDDD\n\n\nEEE";
Console.WriteLine (str.Replace(System.Environment.NewLine, "-"));
/* Result:
AAA
-BBB
-
-
-CCC
DDD---EEE
*/
Console.WriteLine (Regex.Replace(str, #"\r\n?|\n", "-"));
// Result:
// AAA-BBB---CCC---DDD---EEE
Console.WriteLine (Regex.Replace(str, #"[\r\n]+", "-"));
// Result:
// AAA-BBB-CCC-DDD-EEE
}
}
Use new in .NET 6 method
myString = myString.ReplaceLineEndings();
Replaces ALL newline sequences in the current string.
Documentation:
ReplaceLineEndings
Don't forget that replace doesn't do the replacement in the string, but returns a new string with the characters replaced. The following will remove line breaks (not replace them). I'd use #Brian R. Bondy's method if replacing them with something else, perhaps wrapped as an extension method. Remember to check for null values first before calling Replace or the extension methods provided.
string line = ...
line = line.Replace( "\r", "").Replace( "\n", "" );
As extension methods:
public static class StringExtensions
{
public static string RemoveLineBreaks( this string lines )
{
return lines.Replace( "\r", "").Replace( "\n", "" );
}
public static string ReplaceLineBreaks( this string lines, string replacement )
{
return lines.Replace( "\r\n", replacement )
.Replace( "\r", replacement )
.Replace( "\n", replacement );
}
}
To make sure all possible ways of line breaks (Windows, Mac and Unix) are replaced you should use:
string.Replace("\r\n", "\n").Replace('\r', '\n').Replace('\n', 'replacement');
and in this order, to not to make extra line breaks, when you find some combination of line ending chars.
Why not both?
string ReplacementString = "";
Regex.Replace(strin.Replace(System.Environment.NewLine, ReplacementString), #"(\r\n?|\n)", ReplacementString);
Note: Replace strin with the name of your input string.
I needed to replace the \r\n with an actual carriage return and line feed and replace \t with an actual tab. So I came up with the following:
public string Transform(string data)
{
string result = data;
char cr = (char)13;
char lf = (char)10;
char tab = (char)9;
result = result.Replace("\\r", cr.ToString());
result = result.Replace("\\n", lf.ToString());
result = result.Replace("\\t", tab.ToString());
return result;
}
var answer = Regex.Replace(value, "(\n|\r)+", replacementString);
As new line can be delimited by \n, \r and \r\n, first we’ll replace \r and \r\n with \n, and only then split data string.
The following lines should go to the parseCSV method:
function parseCSV(data) {
//alert(data);
//replace UNIX new lines
data = data.replace(/\r\n/g, "\n");
//replace MAC new lines
data = data.replace(/\r/g, "\n");
//split into rows
var rows = data.split("\n");
}
Use the .Replace() method
Line.Replace("\n", "whatever you want to replace with");
Best way to replace linebreaks safely is
yourString.Replace("\r\n","\n") //handling windows linebreaks
.Replace("\r","\n") //handling mac linebreaks
that should produce a string with only \n (eg linefeed) as linebreaks.
this code is usefull to fix mixed linebreaks too.
Another option is to create a StringReader over the string in question. On the reader, do .ReadLine() in a loop. Then you have the lines separated, no matter what (consistent or inconsistent) separators they had. With that, you can proceed as you wish; one possibility is to use a StringBuilder and call .AppendLine on it.
The advantage is, you let the framework decide what constitutes a "line break".
string s = Regex.Replace(source_string, "\n", "\r\n");
or
string s = Regex.Replace(source_string, "\r\n", "\n");
depending on which way you want to go.
Hopes it helps.
If you want to replace only the newlines:
var input = #"sdfhlu \r\n sdkuidfs\r\ndfgdgfd";
var match = #"[\\ ]+";
var replaceWith = " ";
Console.WriteLine("input: " + input);
var x = Regex.Replace(input.Replace(#"\n", replaceWith).Replace(#"\r", replaceWith), match, replaceWith);
Console.WriteLine("output: " + x);
If you want to replace newlines, tabs and white spaces:
var input = #"sdfhlusdkuidfs\r\ndfgdgfd";
var match = #"[\\s]+";
var replaceWith = "";
Console.WriteLine("input: " + input);
var x = Regex.Replace(input, match, replaceWith);
Console.WriteLine("output: " + x);
This is a very long winded one-liner solution but it is the only one that I had found to work if you cannot use the the special character escapes like "\r" and "\n" and \x0d and \u000D as well as System.Environment.NewLine as parameters to thereplace() method
MyStr.replace( System.String.Concat( System.Char.ConvertFromUtf32(13).ToString(), System.Char.ConvertFromUtf32(10).ToString() ), ReplacementString );
This is somewhat offtopic but to get it to work inside Visual Studio's XML .props files, which invoke .NET via the XML properties, I had to dress it up like it is shown below.
The Visual Studio XML --> .NET environment just would not accept the special character escapes like "\r" and "\n" and \x0d and \u000D as well as System.Environment.NewLine as parameters to thereplace() method.
$([System.IO.File]::ReadAllText('MyFile.txt').replace( $([System.String]::Concat($([System.Char]::ConvertFromUtf32(13).ToString()),$([System.Char]::ConvertFromUtf32(10).ToString()))),$([System.String]::Concat('^',$([System.Char]::ConvertFromUtf32(13).ToString()),$([System.Char]::ConvertFromUtf32(10).ToString())))))
Based on #mark-bayers answer and for cleaner output:
string result = Regex.Replace(ex.Message, #"(\r\n?|\r?\n)+", "replacement text");
It removes \r\n , \n and \r while perefer longer one and simplify multiple occurances to one.
how to change
XXX#YYY.ZZZ into XXX_YYY_ZZZ
One way i know is to use the string.replace(char, char) method,
but i want to replace "#" & "." The above method replaces just one char.
one more case is what if i have XX.X#YYY.ZZZ...
i still want the output to look like XX.X_YYY_ZZZ
Is this possible?? any suggestions thanks
So, if I'm understanding correctly, you want to replace # with _, and . with _, but only if . comes after #? If there is a guaranteed # (assuming you're dealing with e-mail addresses?):
string e = "XX.X#YYY.ZZZ";
e = e.Substring(0, e.IndexOf('#')) + "_" + e.Substring(e.IndexOf('#')+1).Replace('.', '_');
Here's a complete regex solution that covers both your cases. The key to your second case is to match dots after the # symbol by using a positive look-behind.
string[] inputs = { "XXX#YYY.ZZZ", "XX.X#YYY.ZZZ" };
string pattern = #"#|(?<=#.*?)\.";
foreach (var input in inputs)
{
string result = Regex.Replace(input, pattern, "_");
Console.WriteLine("Original: " + input);
Console.WriteLine("Modified: " + result);
Console.WriteLine();
}
Although this is simple enough to accomplish with a couple of string Replace calls. Efficiency is something you will need to test depending on text size and number of replacements the code will make.
You can use the Regex.Replace method:
http://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex.replace(v=VS.90).aspx
You can use the following extension method to do your replacement without creating too many temporary strings (as occurs with Substring and Replace) or incurring regex overhead. It skips to the # symbol, and then iterates through the remaining characters to perform the replacement.
public static string CustomReplace(this string s)
{
var sb = new StringBuilder(s);
for (int i = Math.Max(0, s.IndexOf('#')); i < sb.Length; i++)
if (sb[i] == '#' || sb[i] == '.')
sb[i] = '_';
return sb.ToString();
}
you can chain replace
var newstring = "XX.X#YYY.ZZZ".Replace("#","_").Replace(".","_");
Create an array with characters you want to have replaced, loop through array and do the replace based off the index.
Assuming data format is like XX.X#YYY.ZZZ, here is another alternative with String.Split(char seperator):
string[] tmp = "XX.X#YYY.ZZZ".Split('#');
string newstr = tmp[0] + "_" + tmp[1].Replace(".", "_");
I need to remove all chars that cant be part of urls, like spaces ,<,> and etc.
I am getting the data from database.
For Example if the the retrieved data is: Product #number 123!
the new string should be: Product-number-123
Should I use regex? is there a regex pattern for that?
Thanks
Here is a an example on how to generate an url-friendly string from a "normal" string:
public static string GenerateSlug(string phrase)
{
string str = phrase.ToLower();
str = Regex.Replace(str, #"[^a-z0-9\s-]", ""); // invalid chars
str = Regex.Replace(str, #"\s+", " ").Trim(); // convert multiple spaces into one space
str = str.Substring(0, str.Length <= 45 ? str.Length : 45).Trim(); // cut and trim it
str = Regex.Replace(str, #"\s", "-"); // hyphens
return str;
}
You may want to remove the trim-part if you are sure that you always want the full string.
Source
An easy regex to do this is:
string cleaned = Regex.Replace(url, #"[^a-zA-Z0-9]+","-");
To just perform the replacement of special characters like "<" you can use Server.UrlEncode(string s). And you can do the opposite with Server.UrlDecode(string s).
I'm trying to match on some inconsistently formatted HTML and need to strip out some double quotes.
Current:
<input type="hidden">
The Goal:
<input type=hidden>
This is wrong because I'm not escaping it properly:
s = s.Replace(""","");
This is wrong because there is not blank character character (to my knowledge):
s = s.Replace('"', '');
What is syntax / escape character combination for replacing double quotes with an empty string?
I think your first line would actually work but I think you need four quotation marks for a string containing a single one (in VB at least):
s = s.Replace("""", "")
for C# you'd have to escape the quotation mark using a backslash:
s = s.Replace("\"", "");
I didn't see my thoughts repeated already, so I will suggest that you look at string.Trim in the Microsoft documentation for C# you can add a character to be trimmed instead of simply trimming empty spaces:
string withQuotes = "\"hellow\"";
string withOutQotes = withQuotes.Trim('"');
should result in withOutQuotes being "hello" instead of ""hello""
s = s.Replace("\"", "");
You need to use the \ to escape the double quote character in a string.
You can use either of these:
s = s.Replace(#"""","");
s = s.Replace("\"","");
...but I do get curious as to why you would want to do that? I thought it was good practice to keep attribute values quoted?
s = s.Replace("\"",string.Empty);
c#: "\"", thus s.Replace("\"", "")
vb/vbs/vb.net: "" thus s.Replace("""", "")
If you only want to strip the quotes from the ends of the string (not the middle), and there is a chance that there can be spaces at either end of the string (i.e. parsing a CSV format file where there is a space after the commas), then you need to call the Trim function twice...for example:
string myStr = " \"sometext\""; //(notice the leading space)
myStr = myStr.Trim('"'); //(would leave the first quote: "sometext)
myStr = myStr.Trim().Trim('"'); //(would get what you want: sometext)
You have to escape the double quote with a backslash.
s = s.Replace("\"","");
s = s.Replace(#"""", "");
This worked for me
//Sentence has quotes
string nameSentence = "Take my name \"Wesley\" out of quotes";
//Get the index before the quotes`enter code here`
int begin = nameSentence.LastIndexOf("name") + "name".Length;
//Get the index after the quotes
int end = nameSentence.LastIndexOf("out");
//Get the part of the string with its quotes
string name = nameSentence.Substring(begin, end - begin);
//Remove its quotes
string newName = name.Replace("\"", "");
//Replace new name (without quotes) within original sentence
string updatedNameSentence = nameSentence.Replace(name, newName);
//Returns "Take my name Wesley out of quotes"
return updatedNameSentence;
s = s.Replace( """", "" )
Two quotes next to each other will function as the intended " character when inside a string.
if you would like to remove a single character i guess it's easier to simply read the arrays and skip that char and return the array. I use it when custom parsing vcard's json.
as it's bad json with "quoted" text identifiers.
Add the below method to a class containing your extension methods.
public static string Remove(this string text, char character)
{
var sb = new StringBuilder();
foreach (char c in text)
{
if (c != character)
sb.Append(c);
}
return sb.ToString();
}
you can then use this extension method:
var text= myString.Remove('"');